1. Field of the Invention
The present invention relates to a miniature hearing aid, and in particular to a hearing aid with a contact spring configuration.
2. Description of the Prior Art
Due to the limited availability of space in hearing aids, common hearing aids (e.g. DE-AS 25 03 253) are frequently designed such that they can be turned on or off by means of a swivelling battery Compartment, thereby eliminating the need for a separate on/off switch. The two contact springs are positioned relative to the battery compartment in such a way, that they touch the battery only when the compartment is swung fully into the housing of the hearing aid. In this first position ("On"-position) the hearing aid is activated: all components requiring current (including the amplifier) are connected to the voltage source. The swivelling battery compartment can, however, be placed in two additional positions. In a second position ("Off"-position) the compartment is partially swung into the housing. The battery touches at most one Contact spring. Since the battery compartment is still mostly contained within the housing, the battery cannot be removed from or fall out of the compartment. This position corresponds to the hearing aid being completely turned off, sInce all the components requiring current (including the amplifier) are disconnected from the battery. In the third position, the battery compartment is swung completely out of the hearing aid housing ("Battery-change"-position). The battery can be removed while the compartment is situated in the third position.
U.S. Pat. No. 4,783,816 describes a hearing aid to be worn behind the ear, which comprises at its lower end a hinged battery compartment with a latch-notch mechanism. This latch-notch mechanism serves simply as a lock, however, and not, for example, as an on/off switch. Nor can this construction be easily adapted to function as an on/off switch: simply fashioning additional notches for the latch would not be sufficient, since the battery would sit tightly in the compartment in only the innermost latch position. In the outer latch positions, the battery would rattle in the compartment.
In consideration of recent technological innovations relating to the use of remote control and data storage in hearing aids (as described, for example, in U.S. Pat. No. 4,845,755), it becomes disadvantageous to disconnect all the components housed in the hearing aid frOm the voltage source in the "off" position. Doing so eliminates the possibility of utilizing remote control. Besides, by shutting off the hearing aid completely, any control data which was stored in the memory is erased. Thus the data must be reprogrammed every time the hearing aid is turned on.